Where did the nestorians begin?

The Church of the East began in the first century when early missionaries established churches in what is now Iraq. In the 5th century a bishop named Nestorius had a falling out with the pope because he wouldn't preach that Mary was divine. Since Nestorius was from the East, all the churches in the East were labelled "Nestorians" and heretics by the Catholic church, even though they had no heretical beliefs. In the 1980's the pope apologized to the patriarch of the Church of the East for this unfair treatment. Today they are known as Chaldeans or Assyrian Christians and are severely persecuted.